Assessing the potential for post-copulatory sexual selection in elasmobranchs.

This review highlights the potential role that post-copulatory sexual selection plays in elasmobranch reproductive systems and the utility of this group to further understanding of evolutionary responses to the post-copulatory processes of sperm competition and cryptic female choice. The growing genetic evidence for female multiple mating (polyandry) in elasmobranchs is summarized. While polyandry appears to be common in this group, rates of multiple paternity are highly variable between species suggesting that there is large variance in the strength of post-copulatory sexual selection among elasmobranchs. Possible adaptations of traits important for post-copulatory sexual selection are then considered. Particular emphasis is devoted to explore the potential for sperm competition and cryptic female choice to influence the evolution of testes size, sperm morphology, genital morphology and sperm storage organs. Finally, it is argued that future work should take advantage of the wealth of information on these reproductive traits already available in elasmobranchs to gain a better understanding of how post-copulatory sexual selection operates in this group.

17 novel polymorphic microsatellite markers for the giant water bug, Abedus herberti (Belostomatidae).

The giant water bug (Abedus herberti) is a large flightless insect that is a keystone predator in aridland aquatic habitats. Extended droughts, possibly due to climate change and groundwater pumping, are causing once-perennial aquatic habitats to dry, resulting in serious conservation concern for some populations. A. herberti also exhibits exclusive male parental care, which has made it a model organism for studying mating systems evolution. Here we describe 17 novel polymorphic microsatellite loci developed for A. herberti. Number of alleles per locus ranged from 2 to 15, and average observed and expected heterozygosities were 0.579 and 0.697, respectively. These loci can successfully resolve both population genetic structure among sites separated by 3-100 km (FST = 0.08-0.21, P < 0.0001), and divergent mating strategies within local populations, making them highly useful for conservation genetics studies of this vulnerable species.